The objective of this project is to determine if alterations in lymphocyte surface antigen receptors or surface antigens play a role in the pathogenesis of connective tissue diseases. During the coming year our efforts will be concentrated in two main areas. (1) Characterization of antilymphocyte antibodies which we have found in the blood of both patients with systemic lupus and their relatives. (2) Attempts to develop methods for measuring the activity of T-lymphocyte subpopulations, particularly suppressor T-cells, in connective tissue diseases.